1. Field of The Invention
A fluid flow sensor for use with a fluid circulating system to indicate a predetermined rate of fluid flow therethrough.
2. Description of The Prior Art
Fluid flow meters and fluid flow sensors are well known in the art. Commonly such meters and sensors include relatively expensive or complex mechanical and/or electronic systems that are often relatively insensitive to small fluctuations of fluid flow.
U.S. No. 4,550,314 discloses a fluid flow meter having an output level limit monitoring means adapted to detect movement of a mechanical pointer. A light emitting diode and photoresistor cooperatively indicate movement of the mechanical pointer in response to fluid flow through the fluid flow meter.
Additional examples of the prior art are shown in: U.S. No. 1,967,081; U.S. No. 3,150,360; U.S. No. 3,635,678; U.S. No. 3,699,560 and U.S. No. 4,646,796.